Electromagnetic operating means



Aug. 27, 1929. R. w. GOFF ELECTROMAGNETIC OPERATING MEANS Filed Aug. 31, 1925 2 Sheets-Sheet l Inventor: Robert W Goffi bg M Hi6 Att Grheg.

Aug. 27, 1929. R. w. GOFF 1,726,391

ELECTROMAGNETIC OPERATING HEARS Filed Aug. 31, 1925 2.Sheets-Sheet 2 Fig. 5.

Inventor: Robevtw. Goff, by His Attorney.

Patented Aug. 27, 1929.

UNITED STATES 1,726,391 PATENT OFFICE.

ROBERT W. GOFF, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTROMAGNETIC OPERATING MEANS.

Application filed August 31, 1925. Serial No. 53,460.

My invention relates to an improved electromagnetic Operating means for devices of various sorts whereby the operated device is moved from any one of a plurality of definite positions to another of said positions by an operating electromagnet in response to a momentary energization thereof and is then mechanically held in the operated position with the operating electromagnet deenergized. The operating electromagnet isthus energized only during the time the device is being moved from one definite position to another and the operated device is mechanically held in a positive manner in any operated position. I

Although the invention is not necessarily limited thereto, it has a particular application to the operation of remotely controlled switches for starting electric motors, as for instance, electromagnetic motor starting switch mechanism under the control of controlling switch mechanism such as a push button switch mechanism located at a dis tance from the motor, whereby a momentary operation of the push button switch mechanism effects the desired operation of the switch mechanism in the motor circuit.

In carrying the invention into effect in the form which I now regard as the preferred form thereof, I provide an improved latching mechanism between the movable element of the operating electromagnet and the operated device whereby a momentary energiza- 1 tion of the electromagneteffects the operation of the device from any of its definite positions to another and the operated device is mechanically held in the operated position until the electromagnet is again energized. For a better understanding of the invention, reference is had to the accompany ng drawings in which Fig. 1 is a perspective view of my improved operating meansapplied to a motor starting switch, the various parts beingin their respective positions when the switch contacts in the circuit of the motor are in the open position; Fig. 2 is a similar view with the various parts in their respective positions when the motor circuitswiteh contacts are in the closed position; Fig. 3 1s another similar view of the various parts in their respective positions when the operating electromagnet is energized to open the motor circuit switch contacts; Fig. 4 is an end view of the operating means in the initial position thereof corresponding to Fig. 1; Fig.

5 is a similar end view of the operating means corresponding to Fig. 2; Fig; 6 is a similar end view of the operating means with the'various parts thereof in intermediate positions during the transition between the position of the parts in Fig. .5 to the position of these parts in Fig. 4, and Fig. 7 is a very simplified diagram of a motor con- Erol system in. accordance with the invenion.

Referring to the drawings, the electromagnetic operating means 10 is arranged for connection with the shaft 11 carrying switch contact mechanism to be operated by the said operating means. Although, as previously set forth, the invention has a particular application in the operation of switch contact mechanism, nevertheless the operating means is effective to operate other devices as will be understood by those skilled in the art. The electromagnetic operating means comprises an electromagnet 12 having a winding spool 13 thereon and an armature 14; which is pivotally mounted on the shaft 11 so as to rotate with reference thereto. The operating connections between the electromagnet and the switch shaft comprise a latching mechanism 15 which in the present embodiment of the invention consists of the two cams 16 and 17, the link 18 pivotally connected to the armature 14, the pin 19 which cooperates with slots in the cams 16 and 17, the latch 20 and the auxiliary cam 21 which cooperates with the pin 19.

The cam 16 is secured to the shaft 11 for the purpose of operating the shaft and the connection between this cam and the armature 14 of the operating electromagnet is controlledby means of the cam 17 which is mounted on the shaft 11 so as to rotate with respect'thereto. The cam 16 and therefore the switch shaft 11, are biased to their positions as indicated in Figs. 1 and 4 by means of the spring 22 which has one end thereof connected to a hook mounted in the station ary support for the operating means and the other end thereof connected with the cam 16. The latch 20 is pivotally supported in the stationary supporting member '23 and this latch is biased into engagement with the cams 16 and 17 by means of the spring 24" which cooperates with the opposite end of the latch from the end which is pressedinto engagementwith the cams 16 and 17. The pin 19 which is connected to be operated by the armature 14 is biased to the position indicated in Figs. 1 and 4 by means of the auxiliary cam 21. This auxiliary cam is pivotally mounted upon the cam 17 so as to be carried thereby. The cam 21 is so shaped and arranged as to engage with the latch 20 when the cam 17 is out of latching engagement with the latch 20 and thus free to be-rotated counter-clockwise, as shown in Fig. 1. In this way the auxiliary cam 21 is operated about its. pivotal connection with thecam 17 so as to force the pin 19 into locking engagement with the cam slots 25 and 26, as shown in Fig. 1. This pin cooperates with a cam slot 25 in the cam' 16 and with a cam slot 26in the cam 17 to establish the connection between the magnetic member 14 and the switch shaft 11 which operates the switch members to the circuit closing posi- 1tion upon attraction of the magnetic mem- In general it may be said that the cam 17 controls the operating connections between the armature 14 of the operating electromagnet and the switch shaft to eifect an operation of the switch shaft from the normal position indicated in Fig. 1 to the operated position as indicated in Fig. 2, and this cam 17 also controls the latch 20 to effect the release of the latch and permt the switch shaft to return to the normal position in response to a subsequent temporary energization of the operating electromagnet.

In Fig. 7 I have indicated in very simplified diagram the arrangement of my electromagnetic operating means in the control of switch mechanism 27 included in' the circuit of an electric motor 28 which is arranged to be connected to the three phase alternating current supply circuit 29 through the contacts of the switch mechanism 27. Associated with this switch mechanism 27 are the auxiliaryv switch contacts 30 and 31 which control the operating windings 32 and 33 of the electromagnetic operating means. The push button switch 34 is provided for effecting a remote control of the motor 28.

As thus constructed and arranged and,

with .the parts in their respective positions indicated in Figs. 1, 4 and.7, the operation of my invention is as follows: In order to close the switch contacts 27 and thereby connect the motor 28 to the supply circuit 29, the pushbutton 34 will be operated so as to close the circuit through the contact 35 and open the circuit through the contact 36. The winding 32 of the electromagnetic operating means will thereupon be energized through the auxiliary switch 30 and the armature 14 will be at once attracted, rotating clockwise about the switch shaft 11. It will be observed that the auxiliary switch 30 is of the normally closed type and is arranged to be operated to the open position when the switch shaft 11 is rotated to carry the motor switch contacts into the circuit closing position. The auxiliary switch 31, on the other hand, is of the normally open type and is closed simultaneously with the main switch contacts. This limited rotation of the armature will eifect a corresponding rotation of the pin 19 and since this pin is held in engagement with the cam slot 25 of the cam 16 by the auxiliary cam 21, as indicated clearly in Fi 1, the cam 16 will be rotated also in the clockwise direction against the action of the spring 22. lVhen the main switch contact 27 and the auxiliary switch contact 31 are closed by this operation of the switch shaft, the auxiliary contacts 30 will be opened, thereby deenergizing the winding 32 of the electromagnet, and permitting the armature 14 to return to the unattracted position. The various parts will now be in their respective positions as indicated in Figs. 2 and 5 and it will be observed that the latch 20 has been forced by the spring 24 into engagement with the detent 37 of the cam 16 so as to thereby hold this cam and the switch shaft in the operative position so that when the Winding 32 of the electromagnet is deenergiz'ed and the'armature 14 returns to its unattracted position, the main contacts of the switch will nevertheless be maintained closed. It will be observed that auxiliary cam 21 has been moved out of engagement with the pin 19, so that when the armature returns to the unattracted position this pin will be permitted to drop to the position as indicated in Figs. 2 and 5 so that a subsequent operation of the armature to the attracted position will initially effect a clockwise rotation of the cam 17 without disturbing the cam 16. This is due to the fact that the auxiliary cam 21 drops down on the cam 17 since it is not engaged with the latch 20 when the cam 17 is in latching engagement with the latch 20, as shown in Fig. 2.

The tripping operation of the switch is as follows z-lVith the cam 21 dropped down as just described, the pin 19 also will drop down into the lower portion of the cam slot 26 in the cam 17, as shown in Fig. 2. Consequently, upon the next energization of the electromagnet, the magnetic member 14 is attracted and through the connecting link 18 draws the pin 19 upwards. The cam slot 26 is so formed that with the pin in its lower position as shown in Fig. 2, the cam 17 is rotated in a clockwise direction. During this clockwise rotation of the cam 17 the pin 19 slides in the elongated portion of the slot 25 in the cam 16 so that the latter cam is not operated.

In Fig. 6 I have indicated the armature latch 20 so as to release this latch from engagement with the cam 16 by moving the one end of the latch against the action of the spring 24 which presses on the other end of the latch. \Vhen the armature 14 has moved to the fully attracted position, the latch 20 will have been released from engagement with the cam 16. With the cam 16 thus free from the latch 20, the cam 16 together with the switch shaft 11 is rotated in the counter-clockwise direction under the strain of the biasing spring 22 to open the main switch contacts and also the auxiliary switch 31. The elongated portion of the cam slot 25 in the cam 16 permits this movement of the cam 16 without interference with the pin 19. In Fig. 3 I have indicated the various parts in another intermediate position which is subsequent to the intermediate position indicated in Fig. 6 and this Fig. 3,

shows the relative positions of the various parts after the main contacts of the switch have been opened and before the armature 14: has returned to the initial position and the various parts of the operating mechanism have returned to their initial positions as indicated in Fig. 1. It should have been previously mentioned that the opening of the main contacts of the switch is effected by depressing the push button 34: so as to break engagement with the push button contact 35 and make contact with the push button con tact 36, thus completing the circuit for the operating winding 33 of the electromagnet through the auxiliary switch contact 31. As soon as the auxiliary switch 31 is opened the electromagnet 13 is deenergized thereby releasing the electromagnetic member 14 and all the parts return to the initial position shown in Fig. 1.

It will be observed from the above that I haveprovided a very simple and effective operating means whereby the switch contacts or other operated device are effectively mechanically held in each definite position with the electromagnet of the operating means deenergized, and the operating means is so constructed and arranged that the operated device is operated from each of these definite positions to the other by a momentary or temporary energization of the operating electromagnet. This is of particular advantage in large electromagnetic switches and the like which require an appreciable energizing current for the operating electromagnet. In my arrangement, since the operating electromagnet is merely energized during the operating interval and then deenergized, a substantial saving in power is effected, and furthermore, the operating means may be designed entirely for the sole purpose of'operating the device since the operating electromagnet is completely deenergized when the device operated thereby has reached any one of these definite positions.

Although not strictly necessary, I find it desirable to provide a stop 38 for limiting the movement of the cam 16 in the opening movement of the main switch contacts. This stop is desirable in order to not only limit the opening movement of the switch contacts, but also to insure that the various parts of the operating means will be in their respective positions as indicated in Figs. 1 and 4, preparatory to the initial operation of the device.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. Operating means for a device having a plurality of definite positions comprising an electromagnet having a movable magnetic member for controlling the operation of the device between said positions, mechanism controlled by the electromagnet for mechanically holding the device in one of its positions including a pair of independently movable members each having a cam surface, and a member connected with said movable magnetic member to be. operated by the electromagnet and cooperating with the cam surfaces on said pair of members to insure movement of the said members into position for holding the device in one of its definite positions upon each alternate operation of the electromagnet.

2. Operating means for a device biased to a normal position comprising an electromagnet having a movable magnetic member for operating the device to an operated position, mechanism including a pair of independently movable members mounted in opposing spaced relation and each having a cam surface, and a member connected with said magnetic member to be operated by the eleetromagnet and cooperating with the cam surfaces of said pair of members to effect alternately movement of the pair of members to hold the-device in said operated position and to release the device therefrom upon successive operations .of the electromagnet.

3. Operating means for a device biased to a normal position comprising an electrom'agnet having a movable magnetic member for operating the device to an operated position, and mechanism including a pair of coaxially mounted rotatable members, each having a cam surface, and a pin connected with said magnetic member to be operated by the electromagnet and cooperating with the cam surfaces of said pair of members to effect alternately movement of the pair'of members to hold the device in said operated position and to release the device for movement to its normal position upon successive operation of the. electromagnet.

4. Operating means for a device having a plurality of definite positions, comprising an electromagnet having a magnetic movable element for effecting operation of said device to and from said-positions, means controlled by said element for holding said device in one of said positions and for releasing said device for movement to another position, the said means including a pair of independently rotatable cam members, one for effecting the operation of said device to said first position and for holding the same therein, and the other for releasing the holding effect of said first member, and a common operating means for said members operated by said magnetic element into different relations with the cam surfaces of the said members upon successive operations of the electromagnet to alternately hold and to render the members effective to release the device.

5. Operating means for a device pivotally mounted for operation between a plurality of definite positions, comprising an electromagnet having a pivotally mounted magnetic movable element, latching mechanism including cooperating pivotally mounted.

members arranged for connection with said operated device for holding the same in each of its definite positions, and connections between said element and said mechanism through which the element operates the co-' to a normal position and-operable to an operated position, comprising an electromagnet having .a magnetic movable element, a latch for holding said device in said operated osition, and a cam which effects the estab ishment of an operating connection bev tween said element and said device to operate the device from the normal position to said operated positionto be held therein by said latch 'upon a momentary energization of said electromagnet, the said cam operating to release said latch upon a subsequent momentary energization of said electromagnet to permit the said device to return to said normal position.

7. Operating meansfor a device biased to a normal position and operable to an operated position, comprising an electromagnet having a magnetic movable element, a latch for holding said device in said operated position, an operative connection between said element and said device, and a cam which controls said connection and said latch, the said cam rendering said connection operative to move said device from the normal position to said operated position for holding the shaft in an operated position, and a connection between said cams operated by said armature through which upon a temporary energization of said electromagnet the said second cam causes the first cam to operate said shaft from the normal position to an operated position to be held by said latch with the said electromagnet deenergized, and through which a subsequent operation of said armature upon a temporary energization of said electromagnet causes the said second cam to release said catch and permit the shaft to return to the normal position in accordance with the bias thereof.

9. In combination, a shaft biased to a normal position, an electromagnetic operating means therefor having an armature, a .cam secured to said shaft for operating the same, a second campivotally mounted on said shaft for-controlling the operation of said first cam, a latch associated with said cams for holding the shaft in an operated position, and a connection between said armature and said cams, the said connection cooperating with cam slots in said cams to effect an operation of said shaft from the normal position to said operated position to be 'h'e ld'therein by said latch with said electromagnet deenergized in response to a temporary 'energization of said electromagnet and t en in response to a subsequent temporary energization of said electromagnet to ROBERT W. GOFF. 

